1. Field of the Invention
The present invention relates to a droplet dispensing apparatus for precisely dispensing a fixed amount of droplets, and more particularly, to a hollow actuator-driven droplet dispensing apparatus, which includes a tube and a hollow laminated piezoelectric actuator, the piezoelectric actuator constructed by stacking multiple layers of piezoelectric devices, on each of which an electrode is coated, on opposite end surfaces of a hollow piezoelectric ceramic body, such that the tube can be expanded and contracted in response to longitudinal expansion and contraction of the piezoelectric devices so as to take in or dispense content.
The hollow actuator-driven droplet dispensing apparatus of the present invention can precisely control the amount of content to be dispensed from the tube by controlling a voltage supplied to the piezoelectric devices since the actuator is constructed of hollow laminated piezoelectric devices.
2. Description of Related Art
Micro-droplet jetting is applicable to various industries such as precision machines, semiconductors, chemical process equipment, and medical and biological industries. In particular, micro-droplet jetting can be applicable to a fabrication process of next-generation semiconductors and displays. In addition, this technology is applicable to a variety of packages, super-precision color patterning, digital textile printing, molding of miniature parts, chemical analysis equipment, and biochips/biosensors. Micro-droplet jetting is one of the key process technologies in terms of product yield and productivity.
For such micro-droplet jetting, a dispensing method is generally used, to which a pneumatic drive using compressed air and an electronic valve is applied. However, precision is reduced due to the compressibility of air and equipment life is reduced due to nozzle clogging, thereby increasing production cost.
In order to compensate for such drawbacks, a dispensing apparatus for jetting droplets was developed, which is constructed of piezoelectric devices.
A dispenser, based on piezoelectric devices, applies bending strain of a thin disk-type piezoelectric device or actuates a metal diaphragm using the longitudinal displacement of a laminated piezoelectric actuator. However, the existing dispenser has a complicated structure and is bulky.
The information disclosed in this Background of the Invention section is only for enhancement of understanding of the background of the invention and should not be taken as an acknowledgment or any form of suggestion that this information forms the prior art that is already known to a person skilled in the art.